Get Items from Custom Post Type Concurso from Custom Taxonomy Residuo

// WP_Query arguments
$args = array(
	'post_type'              => array( 'concurso' ),
	'nopaging'               => false,
	'posts_per_page'         => '20',
	'order'                  => 'DESC',
	'orderby'                => 'rand',
);

// The Query
$get_concursantes_residuo = new WP_Query( $args );

// The Loop
if ( $get_concursantes_residuo->have_posts() ) {
	while ( $get_concursantes_residuo->have_posts() ) {
		$get_concursantes_residuo->the_post();
		// do something
	}
} else {
	// no posts found
}

// Restore original Post Data
wp_reset_postdata();